The devices for shredding paper documents for information security purpose are known as paper shredder, and are widely used for the disposal of paper documents containing sensitive information.
A paper shredder ensures the security of information by shredding paper documents finely enough for the information contained in the paper documents to be illegible, and recovery and reconstruction of information from shredded paper documents are practically impossible.
In the light of this possible inconvenience, it has been proposed to read the information in the paper documents with an image scanner or the like before they are shredded or otherwise destroyed so that the information read out from the paper documents may be retrieved when required.
Reports, memos and other materials that are handed out in conferences are often double-side prints or copies, and, even in the case of single-side copies or prints, remarks and other notes may be made on the back side of such copies or in the margins of the paper. Therefore, to shred such paper copies after reading all the information it contains, it would be necessary to make a copy of the back side of each sheet of paper, and such copies must be fed into a paper information disposal device along with the original paper documents.
This requires a considerable amount of work to carry out, and if the paper is shredded without due consideration to the remarks and notes made on the back side or in the margin of the paper important information may be destroyed without being read and stored in memory.
Typically, reports and materials used in conferences consist of a plurality of sheets of paper, and they are disposed at the same time. Therefore, a disposal device for paper information is desired to be equipped with paper feed means which allows each sheet of paper to be separated from a stack of paper sheets.
However, it is impossible to totally eliminate the possibility of feeding more than one sheet of paper at a time. If such an error occurs to the paper feed means, the information contained in one or more sheets of paper will be destroyed without being read and stored. This seriously impairs the reliability of the disposal device for paper information, and could cause a serious problem.